Camptothecin and many camptothecin-like compounds, i.e., derivatives have been found to have potent cytotoxicity, and hence, are potent antitumor agents. The camptothecin moiety common to these compounds has a chiral center at the 20 position. The configuration about this position appears to be important to the antitumor activity of camptothecin and its derivatives now in clinical trials. ##STR1##
Camptothecin and its derivatives can be produced using several processes taught in the art such as those described in U.S. Pat. No. 4,894,456; U.S. Pat. No. 4,399,282; U.S. Pat. No. 4,399,276; U.S. Pat. No. 4,943,579; European Patent Application 0 321 122 A2 published Jun. 21, 1989; U.S. Pat. No. 4,473,692; European Patent application No. 0 325 247 A2 published Jul. 26, 1989; European Patent application 0 556 585 A2 published Aug. 25, 1993; U.S. Pat. No. 4,981,968; U.S. Pat. No. 5,049,668; U.S. Pat. No. 5,162,532; U.S. Pat. No. 5,180,722,; and European Patent application 0 540 099 A1 published May 5, 1993.